In surveillance cameras, usually a first manual coarse adjustment is made on the lens focus ring. After that, a fine adjustment of the focus is performed, remotely. The fine adjustment could, e.g., be realized by moving the image sensor in relation to the lens. It is however very difficult to move an image sensor without tilting it at the same time. A problem with tilting the image sensor is that it causes parts of the resulting image to be unfocused. Furthermore, the amount of fine adjustment of the focus is not satisfactory.